[PATCH v2 1/7] ACPI/IORT: Support address size limit for root complexes
From: robin.murphy@arm.com (Robin Murphy)
Date: 2018-07-23 22:16:06
Also in:
linux-acpi, linux-iommu
Subsystem:
acpi, the rest · Maintainers:
"Rafael J. Wysocki", Linus Torvalds
IORT revision D allows PCI root complex nodes to specify a memory address size limit equivalently to named components, to help describe straightforward integrations which don't really warrant a full-blown _DMA method. Now that our headers are up-to-date, plumb it in. If both _DMA and an address size limit are present, we would always expect the former to be a more specific subset of the latter (since it makes little sense for a _DMA range to involve bits which IORT says aren't wired up), thus we can save calculating an explicit intersection of the two effective masks and simply use short-circuit logic instead. Acked-by: Lorenzo Pieralisi <redacted> Reviewed-by: Hanjun Guo <redacted> Signed-off-by: Robin Murphy <robin.murphy@arm.com> --- drivers/acpi/arm64/iort.c | 25 +++++++++++++++++++++++-- 1 file changed, 23 insertions(+), 2 deletions(-)
diff --git a/drivers/acpi/arm64/iort.c b/drivers/acpi/arm64/iort.c
index 7a3a541046ed..4a66896e2aa3 100644
--- a/drivers/acpi/arm64/iort.c
+++ b/drivers/acpi/arm64/iort.c@@ -947,6 +947,24 @@ static int nc_dma_get_range(struct device *dev, u64 *size) return 0; } +static int rc_dma_get_range(struct device *dev, u64 *size) +{ + struct acpi_iort_node *node; + struct acpi_iort_root_complex *rc; + + node = iort_scan_node(ACPI_IORT_NODE_PCI_ROOT_COMPLEX, + iort_match_node_callback, dev); + if (!node || node->revision < 1) + return -ENODEV; + + rc = (struct acpi_iort_root_complex *)node->node_data; + + *size = rc->memory_address_limit >= 64 ? U64_MAX : + 1ULL<<rc->memory_address_limit; + + return 0; +} + /** * iort_dma_setup() - Set-up device DMA parameters. *
@@ -975,10 +993,13 @@ void iort_dma_setup(struct device *dev, u64 *dma_addr, u64 *dma_size) size = max(dev->coherent_dma_mask, dev->coherent_dma_mask + 1); - if (dev_is_pci(dev)) + if (dev_is_pci(dev)) { ret = acpi_dma_get_range(dev, &dmaaddr, &offset, &size); - else + if (ret == -ENODEV) + ret = rc_dma_get_range(dev, &size); + } else { ret = nc_dma_get_range(dev, &size); + } if (!ret) { msb = fls64(dmaaddr + size - 1);
--
2.17.1.dirty